Rushdoony was born in New York City, the son of recently arrived Armenian immigrants. Before his parents fled the Armenian Genocide of 1915, his ancestors had lived in a remote area near Mount Ararat.[7] There are claims that since the year 320, every generation of the Rushdoony family has produced a Christian priest or minister.[8] Rushdoony himself claimed that his ancestors "…would perpetually give a member of their family to be a priest to perform a kind of Aaronic priesthood as in the Old Testament, an hereditary priesthood. Whoever in the family felt called would become the priest. And our family did so. So from the early 300's until now there has always been someone in the ministry in the family."[9] Within weeks of arriving in America, his parents moved to Kingsburg, California, where his father founded an Armenian-speaking Presbyterian church. Except for a time when his father pastored a church in Detroit, Rushdoony grew up on the family farm in Kingsburg.

In Santa Cruz, Rushdoony became a reader of the Christian libertarian magazine Faith and Freedom, which advocated an "anti-tax, non-interventionist, anti-statist economic model" in opposition to Franklin D. Roosevelt's New Deal.[11]Faith and Freedom’s views on government aligned with Rushdoony's fears of centralized government power, given the Rushdoony family's memories of the Armenian Genocide.[12] Rushdoony contributed articles to Faith and Freedom, including one describing his observations of the Duck Valley Indian Reservation, and arguing that government support had reduced residents to "social and personal irresponsibility".[13][14]

Rushdoony and his first wife, Arda, separated in 1957 and later divorced. About this time, Rushdoony transferred his church membership from the Presbyterian Church (USA) to the Orthodox Presbyterian denomination. The Orthodox Presbyterian Church's newsletter, The Presbyterian Guardian reported in July 1958 that the Presbytery of California "the Rev. Rousas J. Rushdoony… was received and a new Orthodox Presbyterian Church organized, consist[ing] of a number of persons who had separated from the Presbyterian Church in the USA of Santa Cruz." The newsletter article goes on to report, "[t]he Presbytery in receiving the church also examined Mr. Thomas Kirkwood and Mr. Kenneth Web as prospective elders, and they with Mr. Rushdoony were constituted the session of the church," and announced the publication of Rushdoony's By What Standard? later that year.[15]

The May 1962 edition of The Presbyterian Guardian reported Rushdoony's resignation, noted as "reportedly to devote his time for his writing and lecturing."[16] Rushdoony also married his second wife, Dorothy Barbara Ross Kirkwood Rushdoony during 1962. She died in 2003.[17]

Rushdoony moved to Los Angeles in 1965 and founded the Chalcedon Foundation; the monthly Chalcedon Report, which Rushdoony edited, began appearing that October.[6] His daughter Sharon later married Gary North, a Christian Reconstructionist writer and economic historian. North and Rushdoony became collaborators until a dispute in 1981 over one of North's articles. Following the dispute, North and Chalcedon continued to independently promote their views, and did not reach a "truce" until 1995.[3]

Under Rushdoony, the Chalcedon Foundation grew to twelve staff members with between 25,000–40,000 people on their mailing lists during the 1980s. Chalcedon and Reconstructionism obtained the support of major Christian book publishers and endorsements from influential evangelical leaders including Pat Robertson, Jerry Falwell and Frank Schaeffer (who later repudiated the movement).[3]

RJ Rushdoony died in 2001 with his children at his side. Rushdoony's biological son, the Rev. Mark R Rushdoony, became and remains the president of the Chalcedon Foundation and editor of the Chalcedon Report. Gary North states that Rushdoony read at least one book a day, six days a week, for fifty years of his life; underlining sentences, and making an index of its main ideas in the rear.[6]

As a theologian Rushdoony saw human beings as primarily religious creatures bound to God, not as rational autonomous thinkers. While this may seem an esoteric theological point, it isn't. All of Rushdoony's influence on the Christian Right stems from this single, essential fact. Many critics of Christian Reconstructionism assume that Rushdoony's unique contribution to the Christian Right was his focus on theocracy. In fact, Rushdoony's primary innovation was his single-minded effort to popularize a pre-Enlightenment, medieval view of a God-centered world. By de-emphasizing humanity's ability to reason independently of God, Rushdoony attacked the assumptions most of us uncritically accept.

Rushdoony developed his philosophy as extension of the work of Calvinist philosopher Cornelius Van Til. Van Til critiqued human knowledge in light of the Calvinist doctrine of total depravity. He argued that sin affected a person's ability to reason. In order to be rational, Van Til claimed, one must presuppose the existence of God and the inerrant, divine inspiration of the (Protestant) Bible.[12] Rushdoony attended to the implications – where Van Til held true knowledge came from God, Rushdoony asserted that "all non-Christian knowledge is sinful, invalid nonsense. The only valid knowledge that non-Christians possess is 'stolen' from 'Christian-theistic' sources."[12] In effect, Rushdoony extended Van Til's thinking from philosophy to "all of life and thought."[8]

By the early 1960s Rushdoony was active in the homeschooling movement, appearing as an expert witness to defend the rights of homeschoolers.[5]

Rushdoony's next focus was on education, especially on behalf of homeschooling, which he saw as a way to combat the intentionally secular nature of the U.S. public school system. He vigorously attacked progressiveschool reformers such as Horace Mann and John Dewey and argued for the dismantling of the state's influence in education in three works: Intellectual Schizophrenia (a general and concise study of education), The Messianic Character of American Education (a history and castigation of public education in the U.S.), and The Philosophy of the Christian Curriculum (a parent-oriented pedagogical statement).

Rushdoony then pursued history – of the world, of the United States, and of the church. He maintained that Calvinistic Christianity provided the intellectual roots for the American Revolution and had thus always had an influential impact in American history. The American Revolution, according to Rushdoony, was a "conservative counterrevolution" to preserve American liberties from British usurpation and it owed nothing to the Enlightenment. He further argued that the United States Constitution was a secular document in appearance only; it didn't need to establish Christianity as an official religion since the states were already Christian establishments.[5] Drawing on the work of theologian Robert Lewis Dabney, Rushdoony argued that the American Civil War "destroyed the early American Republic, which he envisioned as a decentralized Protestant feudal system and an orthodox Christian nation", Rushdoony saw the North's victory as a "defeat for Christian orthodoxy".[18] Some historians have argued that this aspect of Rushdoony's thought has influenced some activists in the Neo-Confederate movement[18] and conservative writers like J. Steven Wilkins.[19] He would further this study in his works on American ideology and historiography, This Independent Republic: Studies in the Nature and Meaning of American History and The Nature of the American System.

Rushdoony's most important area of writing, however, was law and politics, as expressed in his small book of popular essays Law & Liberty and discussed in much greater detail in his three-volume, 1,894-page magnum opus, The Institutes of Biblical Law. With a title modeled after Calvin's Institutes of the Christian Religion, Rushdoony's Institutes was arguably his most influential work. In the book, he proposed that Old Testament law should be applied to modern society and that there should be a Christian theonomy, a concept developed in his colleague Greg Bahnsen's controversial tome Theonomy in Christian Ethics, which Rushdoony heartily endorsed. In the Institutes, Rushdoony supported the reinstatement of the Mosaic law's penal sanctions. Under such a system, the list of civil crimes which carried a death sentence would include homosexuality, adultery, incest, lying about one's virginity, bestiality, witchcraft, idolatry or apostasy, public blasphemy, false prophesying, kidnapping, rape, and bearing false witness in a capital case.[20] Although supporting the separation of church and state at the national level, Rushdoony understood both institutions as under the rule of God,[21] and thus he conceived secularism as posing endless false dichotomies, which his massive work addresses in considerable detail. In short, he sought to cast a vision for the reconstruction of society based on Christian principles.[22]

The book was also critical of democracy. He wrote that "the heresy of democracy has since then worked havoc in church and state ... Christianity and democracy are inevitably enemies." He elsewhere said that "Christianity is completely and radically anti-democratic; it is committed to spiritual aristocracy," and characterized democracy as "the great love of the failures and cowards of life."[8]

Rushdoony's work has been used by Dominion Theology advocates who attempt to implement a Christian theocracy, a government subject to Biblical law, especially the Torah, in the United States. Authority, behavioural boundaries, economics, penology and the like would all be governed by biblical principles in Rushdoony's vision, but he also proposed a wide system of freedom, especially in the economic sphere, and claimed Ludwig von Mises as an intellectual mentor; he called himself a Christian libertarian.[12]

In 1972, Cornelius Van Til "disclaimed affiliation" with Rushdoony and the Christian Reconstructionist movement, writing "...I am frankly a little concerned about the political views of Mr. Rushdoony and Mr. North and particularly if I am correctly informed about some of the views Gary North has with respect to the application of Old Testament principles to our day. My only point is that I would hope and expect they would not claim such views are inherent in the principles I hold".[23]

Rushdoony was, and remains, a controversial figure, as is the Christian Reconstructionist movement in which he was involved.

Pointing to Rushdoony's support for the death penalty, the British Centre for Science Education decried his perceived dislike of democracy and tolerance.[8] Furthermore, Rushdoony has been accused of Holocaust denial and racism.[24] According to Frank Schaeffer, Rushdoony believed that interracial marriage, which he referred to as "unequal yoking", should be made illegal.[25] He also opposed "enforced integration", referred to Southern slavery as "benevolent", and said that "some people are by nature slaves".[26] Kerwin Lee Klein, however, argues that Rushdoony was not a "biological racialist" and that for him "racism founded on modern biology simply represented another pagan revival."[27]

In The Institutes of Biblical Law he uses the 1967 work Judaism and the Vatican by Léon de Poncins as a source for Paul Rassinier's figure of 1.2 million Jewish deaths during the Holocaust, and the claim that Raul Hilberg calculated the number at 896,292, and further asserts that very many of these died of epidemics. He calls the charge of 6 million Jewish deaths "false witness" against Germany.[28][29] In 2000, Rushdoony stated concerning this passage in his Institutes "It was not my purpose to enter a debate over numbers, whether millions were killed, or tens of millions, an area which must be left to others with expertise in such matters. My point then and now is that in all such matters what the Ninth Commandment requires is the truth, not exaggeration, irrespective of the cause one seeks to serve."[30]Carl R. Trueman, Professor of Historical Theology and Church History at Westminster Theological Seminary wrote in 2009 regarding the passage and Rushdoony's Holocaust denial:

His sources are atrocious, secondhand, and unverified; that he held this position speaks volumes about this appalling incompetence as a historian, and one can only speculate as to why he held the position from a moral perspective... He deals with the matter under the issue of the ninth commandment and, ironically breaches it himself in his presentation of the matter.[31]

^Lizza, Ryan (2011-08-15). "Leap of Faith". The New Yorker. ISSN0028-792X. Retrieved 2014-04-23. Wilkins is the leading proponent of the theory that the South was an orthodox Christian nation unjustly attacked by the godless North. This revisionist take on the Civil War, known as the “theological war” thesis, had little resonance outside a small group of Southern historians until the mid-twentieth century, when Rushdoony and others began to popularize it in evangelical circles.

Lane, Frederick S. The court and the cross: the religious right's crusade to reshape the Supreme Court, Beacon Press, 2008, p. 40. "Despite its provocative suggestions, the book [Institutes of Biblical Law] did not receive widespread attention when it was published[...] in part because Rushdoony also used the work to deny the Holocaust, defend segregation and slavery, and condemn interracial, intercultural, and interreligious marriages."

Holthouse, David. "Casting Stones", Intelligence Report, Southern Poverty Law Center, Winter 2005. Retrieved November 4, 2009. "The elder Rushdoony was a racist and Holocaust denier who took his group's name from a medieval council of bishops that proclaimed the subservience of all nations and governments to God."

Schaeffer, Frank. Patience with God: Faith for People Who Don't Like Religion (or Atheism), Da Capo Press, 2009, p. 117. "Rushdoony was also a Holocaust denier."

Trueman, Carl R.Histories and Fallacies: Problems Faced in the Writing of History, Crossway, 2009, p. 30. "While Rushdoony's followers do not like to acknowledge his Holocaust Denial, it is incontestable that he held such a position..."

Brock, David. Blinded by the Right: The Conscience of an Ex-Conservative, Random House of Canada, 2003, p. 201. "Rushdoony was also a Holocaust denier."

Blumenthal, Sidney. The Clinton Wars, Plume, 2004, p. 319. "One of the members of the small founding board, RJ Rushdoony, was a Holocaust denier who favored the death penalty for homosexuals and doctors performing abortions."

^Rushdoony, Rousas J. (1973). The Institutes of Biblical Law. Nutley, NJ: Craig Press. pp. 586, 588. ISBN9780875524108., citing Vicomte de Poncins, Léon (1967). Judaism and the Vatican: An Attempt at Spiritual Subversion. London: Britons Publishing Company. p. 178. "The false witness born during World War II with respect to Germany is especially notable and revealing. The charge is repeatedly made that six million innocent Jews were slain by the Nazis, and the figure—and even larger figures—is now entrenched in the history books. Poncins, in summarizing the studies of the French Socialist, Paul Rassinier, himself a prisoner in Buchenwald, states: Rassinier reached the conclusion that the number of Jews who died after deportation is approximately 1,200,000 and this figure, he tells us, has finally been accepted as valid by the Centre Mondial de Documentation Juive Contemporaine. Likewise he notes that Paul Hilberg, in his study of the same problem, reached a total of 896,292 victims. Very many of these people died of epidemics; many were executed..."